load_cities_list <- function() {
  
  cities_list <- tribble(~input, ~text,
                         "madrid", "spain--madrid",
                         "roma", "italy--roma",
                         "london", "united-kingdom--london",
                         "paris", "france--paris",
                         "barcelona", "spain--barcelona",
                         "san francisco", "ca--san-francisco",
                         "berlin", "germany--berlin",
                         "amsterdam", "netherlands--amsterdam",
                         "warsaw", "poland--warszawa",
                         "lyon", "france--lyon", 
                         "marseille", "france--marseille", 
                         "sevilla", "spain--sevilla", 
                         "vigo", "spain--vigo", 
                         "malaga", "spain--malaga", 
                         "zaragoza", "spain--zaragoza", 
                         "marbella", "spain-marbella", 
                         "bilbao", "spain--bilbao", 
                         "san sebastian", "spain--donostia-san-sebastián", 
                         "cadiz", "spain--cádiz", 
                         "granada", "spain--granada", 
                         "valladolid", "spain--valladolid",
                         "santiago", "chile--santiago",
                         "buenos aires", "argentina--buenos-aires",
                         "sydney", "australia--sydney",
                         "lima", "peru--lima",
                         "glasgow", "united-kingdom--glasgow",
                         "dublin", "ireland--dublin",
                         "lisbon", "portugal--lisboa"
                         
  )
  
  return(cities_list)
}

create_url <- function(city) {
  
  cities_list <- load_cities_list()  # loading city list into function
  
  url_city <- cities_list$text[cities_list$input == city] # returns the city name in Eventbrite's url format 
  
  url_root <- "https://www.eventbrite.es/d/"
  url_suffix <- "/events--tomorrow/" # you can change this to `/events_today/`
  # url_suffix <- "/events--today/" 
  
  # combines the parts of the url to create full url 
  url <- paste0(url_root, url_city, url_suffix)
  
  return(url)
}

count_pages <- function(link){
  
  total_pages <- link |> 
    read_html() |> 
    xml_find_all("//li[@class='eds-pagination__navigation-minimal eds-l-mar-hor-3']") |> 
    xml_text() |> 
    str_extract_all("\\d+$") |> 
    pluck(1) # extracts first item 
  
  total_pages <- as.numeric(total_pages)
  return(total_pages) # returns the number of available pages as an integer
}

get_event_links <- function(link, page_num) {
  
  link_with_page_num <- paste0(link, "?page=", page_num) # adds page number info to url 
  
  html_link <- link_with_page_num |> 
    read_html() |>
    xml_find_all("//section[@class='event-card-details']//div[@class='Stack_root__1ksk7']//a") |> 
    xml_attr("href")
  
  # remove the repeating links that are automatically scraped
  links <- unique(html_link)
  
  return(links) # returns character vector of links
}

get_all_event_links <- function(link) {
  
  all_event_links <- c() # creates empty vector
  
  pages_count <- count_pages(link = link) # gets number of available pages at this link 
  # pages_count <- min(10, pages_count) # don't pull more than 10 pages at once
  
  for (i in 1:pages_count) {
    
    Sys.sleep(2)
    # loops through number of pages 
    # gets a new batch of event links from page i 
    links <- get_event_links(link = link, page_num = i)
    
    # adds it to the full vector of titles 
    all_event_links <- c(all_event_links, links) 
  }
  
  # returns only event links that are not NA and that are unique
  return(unique(all_event_links[!is.na(all_event_links)]))
  
}

get_event_info <- function(link, cityname) {
  
  # data frame for the city with all events 
  shared_df <- data.frame()
  
  # stores all the links we will scrape as character vector
  all_links <- get_all_event_links(link)
  
  # name of the CSV file that will be exported from shared_df
  file_path <- paste0(cityname, format(Sys.Date()+1, "%Y%m%d"), ".csv")
  
  num_all_links <- length(all_links) # number of links/events
  j <- 0 # variable for counting links being scraped 
  
    # Loop over each link in 'all_links'
for (i in seq_along(all_links)) {
  
  Sys.sleep(1)
  
  j <- j + 1 # adds one each loop for counting progress
  
  event_link <- all_links[i]
  
  html <- event_link |> read_html()
  


# Read HTML and extract duration if there is information, if not NA
  
  tryCatch({shared_df[i, "Duration"] <- if (html |>
                                            xml_find_all("//li[@class = 'eds-text-bm eds-text-weight--heavy css-1eys03p']/text()") |>
                                            length() == 0) {
    NA
    } else {
      html |>
        xml_find_all("//li[@class = 'eds-text-bm eds-text-weight--heavy css-1eys03p']/text()") |>
        xml_text() %>%
        .[[1]]
      }
  }, error = function(e) {
    shared_df[i, "Duration"] <- NA
    })
  
  # Extract ticket type
  tryCatch({
    shared_df[i, "Ticket_Type"] <- if (html |>
                                       xml_find_all("//li[@class = 'eds-text-bm eds-text-weight--heavy css-1eys03p']/text()") |>
                                       length() == 0) {
      "Sold out"
      } else {
        html |>
          xml_find_all("//li[@class = 'eds-text-bm eds-text-weight--heavy css-1eys03p']/text()") |>
          xml_text() %>%
          .[[2]]
        }
    }, error = function(e) {
      shared_df[i, "Ticket_Type"] <- NA})
  
  # Extract refund policy. If no info, store as NA
  
  tryCatch({
    shared_df[i, "Refund_Policy"] <- if (html |>
                                         xml_find_all("//div[@class = 'Layout-module__module___2eUcs Layout-module__refundPolicy___fQ8I7']//section[@class = 'event-details__section']/div") |>
                                         length() == 0) {
      NA
      } else {
        html |>
          xml_find_all("//div[@class = 'Layout-module__module___2eUcs Layout-module__refundPolicy___fQ8I7']//section[@class = 'event-details__section']/div") |>
          xml_text() %>%
          .[[2]]
        }
    }, error = function(e) {
      shared_df[i, "Refund_Policy"] <- NA
      })
# Extract description. If no info, save as NA
  tryCatch({
    shared_df[i, "Description"] <- if (html |>
                                       xml_find_all("//div[@class = 'eds-text--left']//p") |>
                                       length() == 0){
      NA
      } else {
        html |>
          xml_find_all("//div[@class = 'eds-text--left']//p") |>
          xml_text() |>
          discard(~.x == "") |>
          paste(collapse = " ")
      }
    }, error = function(e) {
      shared_df[i, "Description"] <- NA
      })
  
  # pull json data
  
  json <-
    html |>
    xml_find_all("//script[@type='application/ld+json']") |>
    pluck(1) |>
    xml_text()
  
  tryCatch({json <- fromJSON(json)},
         error = function(e) {
           json <- NA})
  
  tryCatch({shared_df[i, "LowPrice"] <- json$offers$lowPrice[1]},
           error = function(e) {
             shared_df[i, "LowPrice"] <- NA})
  tryCatch({shared_df[i, "HighPrice"] <- json$offers$highPrice[1]},
           error = function(e) {
             shared_df[i, "HighPrice"] <- NA})
  tryCatch({shared_df[i, "Currency"] <- json$offers$priceCurrency[1]},
           error = function(e) {
             shared_df[i, "Currency"] <- NA})
  tryCatch({shared_df[i, "Organizer"] <- json$organizer$name},
           error = function(e) {
             shared_df[i, "Organizer"] <- NA})
  tryCatch({shared_df[i, "EventStatus"] <- json$eventStatus},
           error = function(e) {
             shared_df[i, "EventStatus"] <- NA})
  tryCatch({shared_df[i, "StartTime"] <- lubridate::as_datetime(json$startDate)},
           error = function(e) {
             shared_df[i, "StartTime"] <- NA})
  tryCatch({shared_df[i, "EndTime"] <- lubridate::as_datetime(json$endDate)},
           error = function(e) {
             shared_df[i, "EndTime"] <- NA})
  tryCatch({shared_df[i, "Title"] <- json$name},
           error = function(e) {
             shared_df[i, "Title"] <- NA})
  tryCatch({shared_df[i, "Subtitle"] <- json$description},
           error = function(e) {
             shared_df[i, "Subtitle"] <- NA})
  tryCatch({shared_df[i, "url"] <- json$url},
           error = function(e) {
             shared_df[i, "url"] <- NA})
  
  shared_df[i, "City"] <- cityname # city variable for when we complile data 
  
  # calculating and reporting the progress of the scraper
  print(paste(round(100 * j/num_all_links, 2), "% completed"))
  
  # read the CSV file with all the previously saved events and save as `res`
  res <- try(read_csv(file_path, show_col_types = FALSE), silent = TRUE)
  
  if (inherits(res, "try-error")) {
    # Save the data frame we scraped above
    print("File doesn't exist; Creating it")
    write_csv(shared_df, file_path)
    } else {
      # If the file was read successfully, append the
      # new rows and save the file again
      combined_df <- bind_rows(res, shared_df[i,])
      write_csv(combined_df, file_path)
    }
  rm(res) # removed `res` to save memory space 
}
  }